1. Field of the invention
The present disclosure relates to a voice coil motor.
2. Description of Related Art
Recently, various optical devices such as a miniature digital camera on a mobile phone or a high resolution digital camera have been developed. In a case of a miniature digital camera applied on a mobile phone, a distance between an image sensor and a lens adjusting a magnification and a focus was uncontrollable in a conventional technology. However, an actuator adjusting the distance between the image sensor and the lens such as a voice coil motor has been recently developed to adjust the function.
A voice coil motor uses a repulsive force and an attractive force generated by a magnetic field of a magnet and a magnetic field of coil to adjust a distance between the image sensor and the lens. The voice coil motor includes a bobbin storing the lens and a leaf spring elastically supporting the bobbin, where the lens is mounted to the bobbin using a screw thread formed at an inner surface of the bobbin.
In mounting the lens to the bobbin using a screw thread formed at an inner surface of the bobbin, the bobbin is generated with a rotational force by rotation of the lens, whereby the lens and the bobbin are rotated by the rotational force.
If the bobbin is rotated, a leaf spring of an extremely thin metal plate coupled to the bobbin and elastically supporting the bobbin is simultaneously rotated, and the leaf spring is thereby damaged or bent to the disadvantage of frequently generating a bad assembly of a voice coil motor.